Přehled

Project summary

Despite a considerable progress in uncovering fundamental molecular processes involved in the regulation of eukaryotic cell polarity, the understanding of this phenomenon in plants is still fragmentary at best. In collaboration with German colleagues we found the possibility of an unexpected co-ordinated involvement of exocyst and a class of plant defence proteins in the regulation of targeted exocytosis; the present project, involving collaboration of both groups, builds on this observation. Exocyst is an evolutionarily conserved cytoplasmic secretory vesicle-tethering complex implicated in the targeting of secretory pathway components to specific plasma membrane (PM) domains; on the contrary, the molecular function of our class of plant defence proteins remains unknown. Unpublished observations in our labs revealed that Arabidopsis loss-of-function mutants in these defence proteins and the exocyst have almost identical phenotypic defects in the biogenesis of secondary cell walls. We aim to elucidate currently unknown molecular mechanism(s) of these defence proteins activity in the context of exocyst function in polarized exocytosis. We shall address the presumed interplay of these proteins in defence as well as in secondary wall biologenesis. Our efforts should substantially contribute to the understanding of the enigmatic molecular mechanism of these defence proteins.